! Missing \endcsname inserted.
<to be read again>
\def
\doifnextoptionalelse #1#2->\def
\nextoptionalcommandyes {#1}\def \nextoptio...
<argument> \setupinterlinespace
[line
\dosetvalue #1#2->\@EA \def \csname #1#2
\endcsname
\p!doassign ...r \else \@EAEAEA #1\fi \fi {#2}{#3}
{#4}
\xprocesscommaitem ...@relax@ #1==\empty \@relax@
\@EAEAEA \xprocesscommaite...
...
l.397 ...font=9pt,\setupinterlinespace[line=2.8ex]
]
I apologize if this is a FAQ: my review of the wiki and of core-tab.tex has been most instructive, but not on this issue.